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目的:研究电针逆转血管紧张素-(1-7)[Ang-(1-7)]在大鼠延髓尾端腹外侧区(CVLM)引起血压降低的作用机制.方法:采用中枢核团微量注射和微透析,以及高效液相色谱(HPLC)荧光检测等技术观察Ang-(1-7)及其选择性受体拮抗剂(D-Ala7)-Ang-(1-7)(Ang-779)在大鼠CVLM引起血压改变时氨基酸类神经递质释放的变化以及电针对血压和氨基酸类递质释放的影响.结果: 在CVLM微量注射Ang-(1-7)可引起血压降低,同时伴该区内兴奋性氨基酸谷氨酸(Glu)释放增多和抑制性氨基酸牛磺酸(Tau)释放减少;相反,在CVLM微量注射Ang-779则可引起血压升高,同时伴Glu释放减少和Tau释放增多.在相当于人足三里穴位电针20 min,可分别抑制在CVLM微量注射Ang-(1-7)或Ang-779所引起的血压降低或升高,同时也能部分抵消注射Ang-(1-7)或Ang-779所引起的Glu、Tau释放的改变.结论:电针逆转Ang-(1-7)或Ang-779在CVLM引起的降压或升压作用可能与Glu、Tau释放量的改变有关.,Objective:To investigate the mechanism of the reversal effect of acupuncture on the fall of blood pressure induced by angiotensin-(1-7)[Ang-(1-7)] in the caudal ventrolateral medulla(CVLM) of rats. Methods: Ang-(1-7) and its selective receptor antagonist (D-Ala7), Ang-(1-7) and Ang-(779) were microinjected into the CVLM respectively to induce the change of blood pressure, during which, the concentrations of amino acid neurotransmitters were detected by means of microdialysis and high performance liquid chromatography(HPLC)combined with fluorescent detector, on the other hand, the effects of electro-acupuncture (EA) on the level of blood pressure and the concentrations of amino acid neurotransmitters were also observed. Results:Unilateral microinjection of Ang-(1-7) into the CVLM could decrease the blood pressure (BP), which was accompanied by an increase in the release of Glu and a decrease in the release of Tau in the same site; Whereas microinjection of Ang-779 into the CVLM could elevate BP, which was accompanied by a decrease in the release of Glu and an increase in the release of Tau; EA at acupoint Zusanli (ST 36) for 20 min could inhibit the fall of blood pressure induced by microinjection of Ang-(1-7) into the CVLM and the elevation of blood pressure induced by microinjection of Ang-779 into the CVLM, and in the meantime, it could inhibit the changes of the release of Glu and Tau induced by microinjection of Ang-(1-7) and Ang-779 into the CVLM. Conclusion: The reversal effect of EA on the fall or elevation of blood pressure induced by microinjection of Ang-(1-7) or Ang-779 into the CVLM might be related to the changes of Glu and Tau release.